Check Logfiles Only a Few Minutes Back

January 4, 2016 admin

This is an update post. Previously I had a post here: http://blog.ls-al.com/check-logfiles-for-recent-entries-only/

The code has been problematic around when a new year starts because of the lack of a year in the log entries. I updated the code a little bit to account for the year ticking over. I may still need to come up with a better way but below seem to work ok.

#!/usr/bin/python
#
 
#: Script Name  : checkLogs.py
#: Version      : 0.0.1.1
#: Description  : Check messages for last x minutes.  Used in conjunction with checkLogs.sh and a cron schedule
 
from datetime import datetime, timedelta
 
#suppressPhrases = ['ssd','offline']
suppressPhrases = []
 
#now = datetime(2015,3,17,7,28,00)                  ## Get time right now. ie cron job execution
now = datetime.now()
day_of_year = datetime.now().timetuple().tm_yday         ## Used for special case when year ticks over. Older log entries should be one year older.
 
## How long back to check. Making it 11 mins because cron runs every 10 mins
checkBack = 11
 
lines = []
 
#print "log entries newer than " + now.strftime('%b %d %H:%M:%S') + " minus " + str(checkBack) + " minutes"
 
with open('/var/adm/messages', 'r') as f:
    for line in f:
      myDate = str(now.year) + " " + line[:15]          ## Solaris syslog format like this: Mar 11 12:47:23 so need to add year
 
      if day_of_year >= 1 and day_of_year <= 31:        ## Brain dead log has no year so special case during January
        if not "Jan" in myDate:         #2015 Dec 30
          myDate = str(now.year -1) + " " + line[:15]
 
      if myDate[3] == " ":                        ## What about "Mar  1" having double space vs "Mar 15". That will break strptime %d.
        myDate = myDate.replace(myDate[3],"0")         ## zero pad string position 4 to make %d work?
 
      #print "myDate: %s and now: %s" % (myDate,now)
      lt = datetime.strptime(myDate,'%Y %b %d %H:%M:%S')
      diff = now - lt
      if diff.days <= 0:
        if lt > now - timedelta(minutes=checkBack):
          #print myDate + " --- diff: " + str(diff)
          match = False
          for s in suppressPhrases:
            i = line.find(s)
            if i > -1:
              match = True
          if not match:
            lines.append(line)
 
if lines:
    message = '\n'.join(lines)
    print message                                  # do some grepping for my specific errors here.. send message per mail...